Propeller for vessels.



Patented oct. m,v |899 J. SfGRANT.

P'noPELLl-:n mn vEssELs.

(ppliction led Aug. 2, 1899.)

(No Model.)

me cams mais co, Mnramwn. whnmum surface of the water at all times.

'may be leftfree without any support.

PATENT Orsi-cn.

JAMES S. GRANT, OF SAN FRANCISCO, CALIFORNIA.

PROPELLER FOR VES'SELS.`

SPECIFICATION forming part of Letters Patent No. 634,574, dated october 1o, 1899.

`Application filed August 2, 1489 9. Serial No. 725,923. (No model.)

To @ZZ whom, it may concern:

Be it known that I, JAMES S. GRANT, a citi-` zen of the United States, residing in the city and county of San Francisco and State of Cali- My invention relates to that class of pro-4 pellers for vessels in which the entire propeller is submerged below the surface of the water and in which the paddles or blades `are arranged to feathenwhen moving in one direction and to act squarelyagainst the water when moving in an opposite or reverse direction. zo blades are placed one above and the other be- In my improved propeller the paddles or low a horizontal plane drawn through the axis about which they move, and instead of revolving in a circle about said axis they re ciprocate back and forth in the arc of a circle, acting against the water as they movel in one direction and feathering so as to cut and move through the water with little resistance as they move back in the reverse direction, all as hereinafter more fully described.

Referring to the accompanying drawings, Figure l is a perspective view showing a pair of my reciprocating propellers mounted at the opposite ends of a shaft. Fig. 2 is a vertical section of one of the hinged blades or paddles and the projecting angular stop. Fig. 3 shows the edge of one of the paddlebars, and Fig. at shows the application of my propeller as a side propeller Vfor a vessel.

A is the propeller-shaft, which is driven by a crank connection at B or in any'other snitable way. The ends ot .this shaft project through the sides of the vessel at a sufcient distance below the water-line to keep the paddles of the propellers submerged below the tremities of the shaft may be supported in a box on an outside beam or timber D, or they On each end of this shaft outside the vessel I secure a propeller, which consists of two par- The exi allel rods, bars, or plates C O, of equal length, secured rrnly and fast at their iniddles to the shaft. In practice I shall'usually employ wide plates or castings, which are straight on one edge and which are made circular on their opposite edges, the c'urvecommencing at the front straight edge at-one end and continuing around to the front straight edge at the opposite end, in which case the plates will be widest at the straight edges and gradually tapering to a knife-edge at the curve. I prefer to employ this form of bar, because it possesses great strength and its sharp edge and tapering body present very little resist-ance in moving through the water;` but it will be evident that any form of bar of suicient strength can be used in the construction of lmy propeller. In the following description I will call this straight fiat edge the front and the curved edge the rear of the plates. Y

At each end of each of thebars or plates C is an angular rarm or projection E,which either forms a part of the bar or plate or is securely fastened to it. extend beyond the front or straight faces of the bars or plates C at an acute angle to the plane of the face. A blade or paddle F eX- tends across the front of the plates or bars C C at each end of the propeller, and the edge ot' each blade or paddle, which is adjacent to to the angle between the fiat faces of the bars or plates and the projection E, is connected 'by a hinge or loose joint g with the plates, so that the blade or paddle will swing freely on the hinge or joint,so as to either lieat against the front of the bars or-plates or when swung outward will'bear against the under faces Ot' the projections in a line tangential to the circle which the hinged edge describes. The free edges of the blades or paddles will then always point toward the shaft A.

' In the operation'of this propeller the power for driving the propeller is applied with a reblades through an arc somewhat less than a half-c`ircle,kso as not to encounter the Adeadcenter of the crank movement. Thiscauses the blades or paddles to open and close automatically in accord with the direction of their movement. For instance, in making the These projections or arms ciprocating. movement, so as to carry the y IOO stroke in one direction thepressure of the Water will close one of the paddles or blades, so that it lies flat against the front of' the bars C and acts against the Water in front of it as a propeller, while the opposite blade or paddle by the same movement is thrown back against the arms or projections E, so as to present its edge to the `water, and it will therefore move through the water during this stroke with very little resistance. On the reverse stroke the two blades reverse automatically-that is, the one that feathered during the previous stroke will be thrown up against the front of the bars C, so as to aet as the propeller, While the one which acted as the propeller during the previous stroke will be feathered automatically, and so on through each stroke or movement of the shaft. These positions are plainly shown by the dotted lines in Fig. 3. The device may also be used as a stern propeller.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

l. A submerged propeller for vessels consisting of two or more parallel bars or plates secured at their middles to the propeller-shaft; a-blade or paddle loosely hinged at its outer edge to each extremity of said parallel bars,

same side of the bars or plates and adapted to close flat against the front edge of the bars or plates when their free edges are pressed inward toward the shaft; a stop or proj eotion connected with said arms and adapted to arrest the outward movement of the free ends of the blades or paddles in a linetangential to the circle described by said blades, and means for producing a reciprocating movement of said propeller-shaft, substantially as described.

2. ln a submerged propeller for vessels 3 vertieal plates for supporting the paddles, said plates having a wide front edge and tapering' on each side toward the rear edge; projectionsat each end of the front edges project- Iing inward at an angle to the plane of the front edge, and blades or paddles hinged loosely at one edge in the angle formed by the front edge and the projection, substantially as described.

In witness whereof I have hereunto signed my name, in the presence of two Witnesses, this 21st day of April, A. D. 1899.

JAMES S. GRANT.

Witnesses:

CHAS. J. ARMBRUSTER, J. H. BAYLEss. 

